A verb expresses an action, a state or a condition, e.g. in Greek γράφω ‘I write’ or ‘I am writing’, πήγαν ‘they went’, θα βρέξει ‘it will rain’, νιώθαμε ‘we felt’, έχεις δει ‘you have seen’, υπάρχουν ‘they exist’. It is generally acknowledged that the verb is the most complex part of the Greek morphological system. Whereas English verbs typically have only a small number of different forms to indicate person, tense, etc. (e.g. ‘write’, ‘writes’, ‘writing’, ‘wrote’, ‘written’ represent all the different possible word forms of the verb ‘to write’), most Greek verbs have several dozen different forms. The reason for this is that Greek verbs are inflected for person, number, tense, aspect, voice and – to some extent – mood. Unlike English, Greek does not have to use subject pronouns. The ending of the verb always makes it clear whether the subject is in the first, second or third person, singular or plural. Thus in the active present tense of γράφω, the six different forms can in themselves indicate the subject of the verb without the need for the subject pronouns ‘I’, ‘you’, ‘we’, etc. which English would have to use. Greek uses the subject pronouns only for emphasis or to make a necessary distinction (see Section 5.1 and Part III, Section 184.108.40.206.2). Tense information is also indicated, to a significant extent, in the endings of the verb, although Greek also employs various other means of expressing tense and mood: these are mainly periphrases, involving a particle or an auxiliary verb. Below we give some general information about the verb system, before proceeding to consider the different types of verb conjugation.